Sony FDR-AX33 grainy quality of 4K dancing lessons videos

I am new to such advanced camera and also 4k. I bought this camera to record my daughter dancing lessons. The conditions in dancing hall are not very good:

- quite dark with some "spot lights"

- I have to record video from the balcony - e.g. quite long distnace (20-25) meters

- typically with zoom

- naturally dancers are moving

I used default setting of the camera with 4k mode. Resulting video is quite dark and grainy....

I hope, that the problem is not in the camera, but just in the settings.... Can somebody, more experienced recommend me what to do? I read other posts mentioning ISO setting. I am just afraid, that if I change ISO I will get "blurry movements"

Re: Sony FDR-AX33 grainy quality of 4K dancing lessons videos

Changing the shutter speed or frame rate may give you blurry movements. Changing the ISO changes the sensitivity to light. A high ISO makes something dark appear brighter but also introduces more grain into the image. Part of the trick is to get a shutter speed that is slow enough and IRIS opening wide enough and ISO that is just right to let enough light in without the image appearing to be too grainy. You are definitely at a disadvantage recording from a distance in a dimly lit room and having to use the zoom option. I can only suggest you mimic the shooting conditions as closely as possible and experiment with the settings before recording the next recital.